X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fconsts.rs;h=c64c00134e89a1e77dadadf5bc306c536aa1b45d;hb=2153abb4124fd3dca018d4adb4e79693f1a9fedd;hp=0e1c1e60178f93f24464b61c0fa99fe2fdd8300b;hpb=8239b7616f90b577f7ca3cbbe26209d100aac2b1;p=rust.git diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs index 0e1c1e60178..c64c00134e8 100644 --- a/clippy_lints/src/consts.rs +++ b/clippy_lints/src/consts.rs @@ -2,19 +2,18 @@ use crate::utils::{clip, higher, sext, unsext}; use if_chain::if_chain; -use rustc::hir::def::{DefKind, Res}; -use rustc::hir::*; -use rustc::lint::LateContext; -use rustc::ty::subst::{Subst, SubstsRef}; -use rustc::ty::{self, Instance, Ty, TyCtxt}; -use rustc::{bug, span_bug}; +use rustc_ast::ast::{FloatTy, LitFloatType, LitKind}; use rustc_data_structures::sync::Lrc; +use rustc_hir::def::{DefKind, Res}; +use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, QPath, UnOp}; +use rustc_lint::LateContext; +use rustc_middle::ty::subst::{Subst, SubstsRef}; +use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::{bug, span_bug}; +use rustc_span::symbol::Symbol; use std::cmp::Ordering::{self, Equal}; -use std::cmp::PartialOrd; use std::convert::TryInto; use std::hash::{Hash, Hasher}; -use syntax::ast::{FloatTy, LitKind}; -use syntax_pos::symbol::Symbol; /// A `LitKind`-like enum to fold constant `Expr`s into. #[derive(Debug, Clone)] @@ -124,7 +123,7 @@ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) (&Self::Str(ref ls), &Self::Str(ref rs)) => Some(ls.cmp(rs)), (&Self::Char(ref l), &Self::Char(ref r)) => Some(l.cmp(r)), (&Self::Int(l), &Self::Int(r)) => { - if let ty::Int(int_ty) = cmp_type.sty { + if let ty::Int(int_ty) = cmp_type.kind { Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty))) } else { Some(l.cmp(&r)) @@ -152,16 +151,18 @@ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) } /// Parses a `LitKind` to a `Constant`. -pub fn lit_to_constant(lit: &LitKind, ty: Ty<'_>) -> Constant { - use syntax::ast::*; - +pub fn lit_to_constant(lit: &LitKind, ty: Option>) -> Constant { match *lit { LitKind::Str(ref is, _) => Constant::Str(is.to_string()), LitKind::Byte(b) => Constant::Int(u128::from(b)), LitKind::ByteStr(ref s) => Constant::Binary(Lrc::clone(s)), LitKind::Char(c) => Constant::Char(c), LitKind::Int(n, _) => Constant::Int(n), - LitKind::Float(ref is, _) | LitKind::FloatUnsuffixed(ref is) => match ty.sty { + LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty { + FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()), + FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()), + }, + LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind { ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()), ty::Float(FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()), _ => bug!(), @@ -174,7 +175,7 @@ pub fn lit_to_constant(lit: &LitKind, ty: Ty<'_>) -> Constant { pub fn constant<'c, 'cc>( lcx: &LateContext<'c, 'cc>, tables: &'c ty::TypeckTables<'cc>, - e: &Expr, + e: &Expr<'_>, ) -> Option<(Constant, bool)> { let mut cx = ConstEvalLateContext { lcx, @@ -189,7 +190,7 @@ pub fn constant<'c, 'cc>( pub fn constant_simple<'c, 'cc>( lcx: &LateContext<'c, 'cc>, tables: &'c ty::TypeckTables<'cc>, - e: &Expr, + e: &Expr<'_>, ) -> Option { constant(lcx, tables, e).and_then(|(cst, res)| if res { None } else { Some(cst) }) } @@ -218,48 +219,41 @@ pub struct ConstEvalLateContext<'a, 'tcx> { impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> { /// Simple constant folding: Insert an expression, get a constant or none. - pub fn expr(&mut self, e: &Expr) -> Option { + pub fn expr(&mut self, e: &Expr<'_>) -> Option { if let Some((ref cond, ref then, otherwise)) = higher::if_block(&e) { return self.ifthenelse(cond, then, otherwise); } - match e.node { - ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id), + match e.kind { + ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id, self.tables.expr_ty(e)), ExprKind::Block(ref block, _) => self.block(block), - ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty(e))), + ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty_opt(e))), ExprKind::Array(ref vec) => self.multi(vec).map(Constant::Vec), ExprKind::Tup(ref tup) => self.multi(tup).map(Constant::Tuple), ExprKind::Repeat(ref value, _) => { - let n = match self.tables.expr_ty(e).sty { - ty::Array(_, n) => n.eval_usize(self.lcx.tcx, self.lcx.param_env), + let n = match self.tables.expr_ty(e).kind { + ty::Array(_, n) => n.try_eval_usize(self.lcx.tcx, self.lcx.param_env)?, _ => span_bug!(e.span, "typeck error"), }; self.expr(value).map(|v| Constant::Repeat(Box::new(v), n)) }, ExprKind::Unary(op, ref operand) => self.expr(operand).and_then(|o| match op { - UnNot => self.constant_not(&o, self.tables.expr_ty(e)), - UnNeg => self.constant_negate(&o, self.tables.expr_ty(e)), - UnDeref => Some(o), + UnOp::UnNot => self.constant_not(&o, self.tables.expr_ty(e)), + UnOp::UnNeg => self.constant_negate(&o, self.tables.expr_ty(e)), + UnOp::UnDeref => Some(o), }), ExprKind::Binary(op, ref left, ref right) => self.binop(op, left, right), ExprKind::Call(ref callee, ref args) => { // We only handle a few const functions for now. if_chain! { if args.is_empty(); - if let ExprKind::Path(qpath) = &callee.node; + if let ExprKind::Path(qpath) = &callee.kind; let res = self.tables.qpath_res(qpath, callee.hir_id); if let Some(def_id) = res.opt_def_id(); - let get_def_path = self.lcx.get_def_path(def_id, ); - let def_path = get_def_path - .iter() - .copied() - .map(Symbol::as_str) - .collect::>(); - if def_path[0] == "core"; - if def_path[1] == "num"; - if def_path[3] == "max_value"; - if def_path.len() == 4; + let def_path: Vec<_> = self.lcx.get_def_path(def_id).into_iter().map(Symbol::as_str).collect(); + let def_path: Vec<&str> = def_path.iter().take(4).map(|s| &**s).collect(); + if let ["core", "num", int_impl, "max_value"] = *def_path; then { - let value = match &*def_path[2] { + let value = match int_impl { "" => i8::max_value() as u128, "" => i16::max_value() as u128, "" => i32::max_value() as u128, @@ -281,12 +275,12 @@ pub fn expr(&mut self, e: &Expr) -> Option { #[allow(clippy::cast_possible_wrap)] fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option { - use self::Constant::*; + use self::Constant::{Bool, Int}; match *o { Bool(b) => Some(Bool(!b)), Int(value) => { let value = !value; - match ty.sty { + match ty.kind { ty::Int(ity) => Some(Int(unsext(self.lcx.tcx, value as i128, ity))), ty::Uint(ity) => Some(Int(clip(self.lcx.tcx, value, ity))), _ => None, @@ -297,10 +291,10 @@ fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option { } fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option { - use self::Constant::*; + use self::Constant::{Int, F32, F64}; match *o { Int(value) => { - let ity = match ty.sty { + let ity = match ty.kind { ty::Int(ity) => ity, _ => return None, }; @@ -318,30 +312,28 @@ fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option { /// Create `Some(Vec![..])` of all constants, unless there is any /// non-constant part. - fn multi(&mut self, vec: &[Expr]) -> Option> { + fn multi(&mut self, vec: &[Expr<'_>]) -> Option> { vec.iter().map(|elem| self.expr(elem)).collect::>() } - /// Lookup a possibly constant expression from a ExprKind::Path. - fn fetch_path(&mut self, qpath: &QPath, id: HirId) -> Option { - use rustc::mir::interpret::GlobalId; - + /// Lookup a possibly constant expression from a `ExprKind::Path`. + fn fetch_path(&mut self, qpath: &QPath<'_>, id: HirId, ty: Ty<'cc>) -> Option { let res = self.tables.qpath_res(qpath, id); match res { - Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => { + Res::Def(DefKind::Const | DefKind::AssocConst, def_id) => { let substs = self.tables.node_substs(id); let substs = if self.substs.is_empty() { substs } else { substs.subst(self.lcx.tcx, self.substs) }; - let instance = Instance::resolve(self.lcx.tcx, self.param_env, def_id, substs)?; - let gid = GlobalId { - instance, - promoted: None, - }; - let result = self.lcx.tcx.const_eval(self.param_env.and(gid)).ok()?; + let result = self + .lcx + .tcx + .const_eval_resolve(self.param_env, def_id, substs, None, None) + .ok() + .map(|val| rustc_middle::ty::Const::from_value(self.lcx.tcx, val, ty))?; let result = miri_to_const(&result); if result.is_some() { self.needed_resolution = true; @@ -354,7 +346,7 @@ fn fetch_path(&mut self, qpath: &QPath, id: HirId) -> Option { } /// A block can only yield a constant if it only has one constant expression. - fn block(&mut self, block: &Block) -> Option { + fn block(&mut self, block: &Block<'_>) -> Option { if block.stmts.is_empty() { block.expr.as_ref().and_then(|b| self.expr(b)) } else { @@ -362,7 +354,7 @@ fn block(&mut self, block: &Block) -> Option { } } - fn ifthenelse(&mut self, cond: &Expr, then: &Expr, otherwise: Option<&Expr>) -> Option { + fn ifthenelse(&mut self, cond: &Expr<'_>, then: &Expr<'_>, otherwise: Option<&Expr<'_>>) -> Option { if let Some(Constant::Bool(b)) = self.expr(cond) { if b { self.expr(&*then) @@ -374,11 +366,11 @@ fn ifthenelse(&mut self, cond: &Expr, then: &Expr, otherwise: Option<&Expr>) -> } } - fn binop(&mut self, op: BinOp, left: &Expr, right: &Expr) -> Option { + fn binop(&mut self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option { let l = self.expr(left)?; let r = self.expr(right); match (l, r) { - (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).sty { + (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).kind { ty::Int(ity) => { let l = sext(self.lcx.tcx, l, ity); let r = sext(self.lcx.tcx, r, ity); @@ -468,9 +460,9 @@ fn binop(&mut self, op: BinOp, left: &Expr, right: &Expr) -> Option { } pub fn miri_to_const(result: &ty::Const<'_>) -> Option { - use rustc::mir::interpret::{ConstValue, Scalar}; + use rustc_middle::mir::interpret::{ConstValue, Scalar}; match result.val { - ConstValue::Scalar(Scalar::Raw { data: d, .. }) => match result.ty.sty { + ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data: d, .. })) => match result.ty.kind { ty::Bool => Some(Constant::Bool(d == 1)), ty::Uint(_) | ty::Int(_) => Some(Constant::Int(d)), ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits( @@ -480,7 +472,7 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { d.try_into().expect("invalid f64 bit representation"), ))), ty::RawPtr(type_and_mut) => { - if let ty::Uint(_) = type_and_mut.ty.sty { + if let ty::Uint(_) = type_and_mut.ty.kind { return Some(Constant::RawPtr(d)); } None @@ -488,8 +480,8 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { // FIXME: implement other conversions. _ => None, }, - ConstValue::Slice { data, start, end } => match result.ty.sty { - ty::Ref(_, tam, _) => match tam.sty { + ty::ConstKind::Value(ConstValue::Slice { data, start, end }) => match result.ty.kind { + ty::Ref(_, tam, _) => match tam.kind { ty::Str => String::from_utf8( data.inspect_with_undef_and_ptr_outside_interpreter(start..end) .to_owned(), @@ -500,6 +492,41 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { }, _ => None, }, + ty::ConstKind::Value(ConstValue::ByRef { alloc, offset: _ }) => match result.ty.kind { + ty::Array(sub_type, len) => match sub_type.kind { + ty::Float(FloatTy::F32) => match miri_to_const(len) { + Some(Constant::Int(len)) => alloc + .inspect_with_undef_and_ptr_outside_interpreter(0..(4 * len as usize)) + .to_owned() + .chunks(4) + .map(|chunk| { + Some(Constant::F32(f32::from_le_bytes( + chunk.try_into().expect("this shouldn't happen"), + ))) + }) + .collect::>>() + .map(Constant::Vec), + _ => None, + }, + ty::Float(FloatTy::F64) => match miri_to_const(len) { + Some(Constant::Int(len)) => alloc + .inspect_with_undef_and_ptr_outside_interpreter(0..(8 * len as usize)) + .to_owned() + .chunks(8) + .map(|chunk| { + Some(Constant::F64(f64::from_le_bytes( + chunk.try_into().expect("this shouldn't happen"), + ))) + }) + .collect::>>() + .map(Constant::Vec), + _ => None, + }, + // FIXME: implement other array type conversions. + _ => None, + }, + _ => None, + }, // FIXME: implement other conversions. _ => None, }